Read fault address on arm64 using proposed kernel API.
On aarch64, the top 8 bits of the address (i.e. the tag bits) of
the fault address in si_addr are always clear. This isn't ideal for
MTE which will require these bits in order to correctly diagnose
tag mismatches.
A proposed kernel patch [1] exposes the full fault address including
the tag bits as part of the ucontext. Change debuggerd to read this
fault address if available.
[1] https://patchwork.kernel.org/patch/11435077/
Bug: 135772972
Change-Id: Ia05be574113860f4e9ecc36a310c4b740e0c4afb
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index b3f059c..70b8817 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -154,16 +154,16 @@
}
static void dump_signal_info(log_t* log, const ThreadInfo& thread_info,
- unwindstack::Memory* process_memory) {
+ const ProcessInfo& process_info, unwindstack::Memory* process_memory) {
char addr_desc[64]; // ", fault addr 0x1234"
- if (signal_has_si_addr(thread_info.siginfo)) {
- void* addr = thread_info.siginfo->si_addr;
+ if (process_info.has_fault_address) {
+ size_t addr = process_info.fault_address;
if (thread_info.siginfo->si_signo == SIGILL) {
uint32_t instruction = {};
- process_memory->Read(reinterpret_cast<uint64_t>(addr), &instruction, sizeof(instruction));
- snprintf(addr_desc, sizeof(addr_desc), "%p (*pc=%#08x)", addr, instruction);
+ process_memory->Read(addr, &instruction, sizeof(instruction));
+ snprintf(addr_desc, sizeof(addr_desc), "0x%zx (*pc=%#08x)", addr, instruction);
} else {
- snprintf(addr_desc, sizeof(addr_desc), "%p", addr);
+ snprintf(addr_desc, sizeof(addr_desc), "0x%zx", addr);
}
} else {
snprintf(addr_desc, sizeof(addr_desc), "--------");
@@ -384,7 +384,7 @@
dump_thread_info(log, thread_info);
if (thread_info.siginfo) {
- dump_signal_info(log, thread_info, unwinder->GetProcessMemory().get());
+ dump_signal_info(log, thread_info, process_info, unwinder->GetProcessMemory().get());
}
std::unique_ptr<GwpAsanCrashData> gwp_asan_crash_data;